Capacitive tension wire instrument and displacement monitoring method

Abstract

The invention relates to the technical field of displacement monitoring, in particular to a capacitive tension wire instrument and a displacement monitoring method, and the capacitive tension wire instrument comprises a movable sensing part arranged on a reference wire body, a first plate capacitor and a second plate capacitor; detection spaces are arranged in the first plate capacitor and the second plate capacitor, and the movable sensing parts are arranged in the detection spaces; when the movable sensing part is located in the detection space and displaces, the capacitance of the first plate capacitor and the capacitance of the second plate capacitor are changed. As a signal line does not need to be led out from the movable induction part during measurement, external force interference on a reference line body due to the fact that the signal line needs to be led out from a middle pole of an existing capacitive tension wire instrument is avoided, and the measurement precision of a system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of displacement monitoring, and in particular to a capacitive tensioning wire instrument and a displacement monitoring method. Background Art

[0002] The tension wire method is an important and effective technical means to monitor the horizontal deformation of large structures such as dams. The ideal tension wire is a free wire that is inherently taut and unaffected by external forces in the measurement direction.

[0003] The existing typical capacitive tensioning wire instrument consists of a reference wire (steel wire or carbon fiber wire, etc.) stretched between the fixed end and the tensioning end. One or more capacitive tensioning wire instruments are installed on the measured part (dam section). When the measured part undergoes horizontal displacement relative to the reference wire, the middle pole of the tensioning wire instrument fixed on the reference wire will move away from one of the plates and move closer to the other. Accordingly, the capacitance between the middle pole and the plate closer to it (denoted as C1) will increase, and the capacitance between the middle pole and the plate farther away from it (denoted as C2) will decrease. By measuring C1 and C2, and calculating C1-C2

[0004] C1+C2 can be used to obtain the displacement value between the location of the tensioning wire instrument and the reference wire body.

[0005] The reference wire of a typical existing capacitive tensioning wire gauge is mechanically in contact with the measured part. During measurement, a signal wire must be drawn from the middle pole, which applies a small pulling force perpendicular to the reference wire. When the wire is long and multiple tensioning wire gauges are installed, multiple small pulling forces are applied perpendicular to the reference wire. These small pulling forces, amplified by the lever effect, restrict the measurement accuracy of the entire wire. In addition, in actual use, when a tensioning wire gauge based on the existing cylindrical middle pole design structure is used, the nonlinearity of the measurement results will deteriorate significantly when the measured part undergoes a large displacement relative to the reference wire, causing the middle pole to deviate far from the center of the two plates.

[0006] Therefore, a capacitive tensioning wire instrument and a displacement monitoring method are proposed. Summary of the Invention

[0007] Therefore, the technical problem to be solved by the present invention is that the measurement results of the traditional capacitive wire tensioning instrument are easily affected by the middle pole lead, resulting in deviation and poor linearity.

[0008] The above technical problem is solved by the following technical solution: The present invention provides a capacitive wire tensioning instrument, comprising a movable sensing component provided on a reference wire body, and a first flat plate capacitor and a second flat plate capacitor;

[0009] A detection space is provided in each of the first flat capacitor and the second flat capacitor, and the movable sensing component is provided in the detection space;

[0010] When the movable sensing component is located in the detection space and is displaced, the capacitances of the first flat plate capacitor and the second flat plate capacitor are changed.

[0011] In a preferred embodiment of the capacitive wire tensioning instrument of the present invention, a hanging connection piece is provided on the movable sensing component, and the movable sensing component is connected to the reference wire body through the hanging connection piece.

[0012] In a preferred embodiment of the capacitive wire tensioner of the present invention, the suspension connector is made of non-metallic material.

[0013] In a preferred embodiment of the capacitive wire tensioner of the present invention, the movable sensing component is made of metal.

[0014] In a preferred embodiment of the capacitive wire tensioning instrument of the present invention: the first flat plate capacitor includes a first electrode plate and a second electrode plate, and the gap between the first electrode plate and the second electrode plate is a detection space;

[0015] The second flat plate capacitor includes a third plate and a fourth plate, and a gap between the third plate and the fourth plate is a detection space.

[0016] In a preferred embodiment of the capacitive wire tensioner of the present invention, the movable sensing component is a cuboid.

[0017] In a preferred embodiment of the capacitive wire tensioning instrument of the present invention, the surface of the movable sensing component is parallel to the surfaces of the first electrode plate, the second electrode plate, the third electrode plate, and the fourth electrode plate.

[0018] In a preferred embodiment of the capacitive wire tensioner of the present invention, the thickness of the movable sensing component is smaller than the width of the detection space.

[0019] The present invention also proposes a displacement monitoring method, comprising:

[0020] Build the reference line body;

[0021] Set the measured part on the reference line;

[0022] A movable sensing component perpendicular to the reference line is provided on the measured part;

[0023] Two sets of flat plate capacitors are arranged outside the movable sensing component;

[0024] When the measured part undergoes horizontal displacement in a direction perpendicular to the reference line, the length of the movable sensing component in one set of flat plate capacitors will decrease, and the length of the movable sensing component in the other set of flat plate capacitors will increase.

[0025] In a preferred embodiment of the displacement monitoring method of the present invention: when the measured part undergoes horizontal displacement perpendicular to the reference line, the capacitances of the two sets of flat plate capacitors are calculated, and the horizontal displacement of the measured part is calculated based on the difference in the changes of the two sets of flat plate capacitors.

[0026] The beneficial effect of the present invention is that since there is no need to lead out a signal line from the movable sensing component during measurement, the external force interference to the reference line body caused by the existing capacitive tensioning wire instrument due to the need to lead out the signal line from the middle pole is avoided, thereby improving the measurement accuracy of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings of the embodiments of the present invention. Obviously, the drawings described below only relate to some embodiments of the present invention, and are not intended to limit the present invention.

[0028] Figure 1 The figure shows the overall structure of the capacitive wire tensioner of the present invention.

[0029] Figure 2 The figure shows the connection structure diagram of the movable sensing component and the suspension connection piece of the capacitive tensioning wire instrument of the present invention.

[0030] Figure 3 A schematic structural diagram of the first flat plate capacitor and the second flat plate capacitor of the capacitive wire tensioning instrument of the present invention is shown.

[0031] Figure 4 The schematic diagram of the variable gap capacitive sensor of the present invention is shown.

[0032] Figure 5 The figure shows the structural diagram of the existing capacitive tensioning wire instrument.

[0033] Figure 6 A schematic diagram of the observation principle of the tension line method is shown.

[0034] Figure 7 The schematic diagram of the contact capacitive displacement sensor of the existing capacitive tensioning wire instrument is shown. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below with reference to specific embodiments and the accompanying drawings.

[0036] The terms used in the present invention are those commonly used in the art in view of the functions of the present invention, but these terms may vary according to the intentions of those skilled in the art, precedents, or new technologies in the art. In addition, specific terms may be selected by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the present invention. Therefore, the terms used in the specification should not be understood as simple names, but rather as the meanings of the terms and the overall description of the present invention.

[0037] Reference Figure 1 , this embodiment provides a capacitive wire tensioning instrument, comprising a movable sensing component 1 provided on a reference wire body, and a first flat plate capacitor 2 and a second flat plate capacitor 3;

[0038] A detection space is provided in each of the first flat capacitor 2 and the second flat capacitor 3, and the movable sensing component 1 is provided in the detection space;

[0039] When the movable sensing component 1 is located in the detection space and is displaced, the capacitances of the first flat plate capacitor 2 and the second flat plate capacitor 3 are changed.

[0040] When in use, the displacement of the detected part relative to the reference line can be determined by detecting the change in the size of the capacitance.

[0041] Reference Figure 2 As an optional embodiment: a hanging connection member 11 is provided on the movable sensing component 1, and the movable sensing component 1 is connected to the reference line body through the hanging connection member 11.

[0042] The suspension connector 11 is made of non-metallic material. The non-metallic suspension connector 11 can improve the accuracy of the measurement result and avoid affecting the capacitance of the first flat plate capacitor 2 and the second flat plate capacitor 3 .

[0043] As an optional embodiment: the movable sensing component 1 is made of metal.

[0044] Reference Figure 3 As an optional embodiment: the first flat plate capacitor 2 includes a first electrode plate 21 and a second electrode plate 22, and the gap between the first electrode plate 21 and the second electrode plate 22 is a detection space;

[0045] The second flat plate capacitor 3 includes a third plate 31 and a fourth plate 32 , and the gap between the third plate 31 and the fourth plate 32 is a detection space.

[0046] As an optional embodiment: the movable sensing component 1 is a rectangular parallelepiped, and the structure of the rectangular parallelepiped is convenient for movement in the detection space to change the distance between the plates, thereby changing the capacitance between the plates.

[0047] The two side surfaces of the movable sensing component 1 are parallel to the surfaces of the first electrode plate 21 , the second electrode plate 22 , the third electrode plate 31 and the fourth electrode plate 32 . The parallel arrangement can improve the linearity of the measurement and reduce the error during detection.

[0048] The thickness of the movable sensing component 1 is smaller than the width of the detection space. The smaller the gap between the movable sensing component 1 and the detection space, the more sensitive the detection result.

[0049] The present invention also proposes a displacement monitoring method, comprising:

[0050] Build the reference line body;

[0051] Set the measured part on the reference line;

[0052] A movable sensing component 1 perpendicular to the reference line is provided on the measured part;

[0053] Two sets of flat plate capacitors are arranged outside the movable sensing component 1;

[0054] It should be noted that several measured parts or one measured part can be set on the reference line.

[0055] When the measured part undergoes horizontal displacement in a direction perpendicular to the reference line, the length of the movable sensing component 1 in one group of flat plate capacitors will decrease, and the length in the other group of flat plate capacitors will increase.

[0056] When the measured part undergoes horizontal displacement in a direction perpendicular to the reference line, the capacitances of the two sets of plate capacitors are calculated, and the horizontal displacement of the measured part is calculated based on the difference in the capacitance between the two sets of plate capacitors.

[0057] It should be noted that, referring to Figure 6 , is a schematic diagram of the observation principle of the tension wire method. The tension wire method is an important and effective technical means to observe the horizontal deformation of the appearance of large buildings such as dams. The ideal tension wire is a free wire that is tensioned and not affected by external forces in the measurement direction. Figure 6 As shown in the tension line observation system, the tensioned tension line is used to provide a reference benchmark (representing the positions of the two end points) for each observation point (tension line instrument) arranged along the line. Figure 7 , which is the principle diagram of the contact capacitive displacement sensor of the existing capacitive tensioning wire instrument. The capacitance formula of the ideal parallel plate capacitor is Where ε is the dielectric constant of the material (air) between the two plates, s is the area of the plates, and d is the distance between the two plates. The capacitance can be changed by changing the size of ε, s or d. The plates P1 and P2 have the same geometric dimensions and a fixed relative position (distance D). The capacitances between the intermediate pole Px and the plates P1 and P2 are When the position (d1, d2) of the middle pole Px relative to the pole plates P1 and P2 changes, one of C1 and C2 will become larger and the other will become smaller. (D=d1+d2), the exact position of Px between the plates P1 and P2 can be determined.

[0058] Reference Figure 5 , is a structural diagram of an existing capacitive tensioning wire meter. A reference wire body (steel wire or carbon fiber wire, etc.) is tensioned between a fixed end and a tensioning end, and one or more capacitive tensioning wire meters are respectively installed on the measured part (dam section). The two plates of the tensioning wire meter have the same geometric dimensions and a fixed relative position (distance D). The plates are installed together with the base at the measured part (dam section), and the cylindrical middle pole is fixed on the reference wire body. When the measured part undergoes horizontal displacement relative to the reference wire body in the vertical direction, the middle pole of each tensioning wire meter fixed on the reference wire body will move away from one of the plates and approach the other plate. Accordingly, the capacitance between the middle pole and the plate approaching it (denoted as C1) will increase, and the capacitance between the middle pole and the plate moving away from it (denoted as C2) will decrease. By measuring and calculate The displacement value of the position where the tensioning wire instrument is located relative to the reference wire body can be obtained.

[0059] In a typical capacitive tensioner, the reference wire and the measured part are mechanically in contact. Because C1 and C2 need to be measured separately, a signal line is drawn from the center pole (Px) to the local measurement circuit (located above the measurement dam section). This signal line applies a small tensile force perpendicular to the reference wire. When the wire is long and multiple tensioners are installed, multiple small tensile forces are applied perpendicular to the reference wire. These forces, amplified by the leverage effect, can limit the measurement accuracy of the entire wire.

[0060] In addition, in actual applications of the tension wire meter based on the existing cylindrical intermediate pole design structure, when the measured part undergoes a large displacement relative to the reference line body, causing the intermediate pole to deviate far from the middle of the two plates, the nonlinearity of the measurement results will deteriorate significantly.

[0061] Reference Figures 1 to 4 , which is a non-contact capacitive wire tensioning instrument proposed by the present invention. The first flat plate capacitor 2 and the second flat plate capacitor 3 have the same structure and size. The movable sensing component 1 is a rectangular metal, and its length and width are slightly smaller than the first electrode plate 21, the second electrode plate 22, the third electrode plate 31, and the fourth electrode plate 32. It is fixed to the reference wire body through a non-metallic suspension connector 11, and the side plane of the movable sensing component 1 is perpendicular to the reference wire body.

[0062] When in use, the first flat plate capacitor 2 and the second flat plate capacitor 3 are installed at the measured part (dam section). The positions of the first electrode plate 21, the second electrode plate 22, the third electrode plate 31, and the fourth electrode plate 32 represent the actual position of the measured part, and the position of the reference line represents the actual position of the two endpoints. The initial position of the movable sensing component 1 is located between the first flat plate capacitor 2 and the second flat plate capacitor 3. When the measured part undergoes horizontal displacement in the vertical direction relative to the reference line, the length of the movable sensing component 1 in one group of flat plate capacitors will decrease, and the length in the other group of flat plate capacitors will increase. Accordingly, the capacitance between the group of flat plate capacitors reduced by the movable sensing component 1 (denoted as C1) will decrease, and the capacitance between the group of flat plate capacitors increased by the movable sensing component 1 (denoted as C2) will increase. By measuring C1 and C2, and calculating The displacement value of the position where the tensioning wire instrument is located relative to the reference wire body can be obtained.

[0063] In the present invention, the movable sensing component 1 suspended above the reference line body has no mechanical connection with the outside, and has no adverse effect on the freedom of the reference line body. At the same time, the mechanical structure of this solution is closer to an ideal flat plate capacitor. Compared with the existing solution, the nonlinearity caused by the edge effect of the capacitor is also greatly reduced.

[0064] The present invention adds a set of capacitor plates and replaces the cylindrical middle pole originally fixed on the reference line with the movable sensing component 1 of the present invention. The two side planes of the movable sensing component 1 are perpendicular to the reference line. By changing the length of the movable sensing component 1 in the two sets of flat plate capacitors, the capacitance between the two sets of flat plate capacitors is changed. By directly measuring C1 and C2 and calculating The corresponding position of the active sensing component 1 in the two sets of flat-plate capacitors can be obtained, and the displacement between the reference wire and the location of the flat-plate capacitors can be calculated. Since the measurement does not require a signal line to be drawn from the active sensing component 1, the external force interference on the reference wire caused by the need to draw a signal line from the middle pole of existing capacitive wire tensioning instruments is avoided.

[0065] At the same time, the movable sensing component 1 in the present invention is a rectangular metal, whose length and width are slightly smaller than the first electrode plate 21, the second electrode plate 22, the third electrode plate 31, and the fourth electrode plate 32. The mechanical structure is closer to an ideal flat plate capacitor. Compared with the existing solution, the nonlinearity caused by the edge effect of the capacitor is also greatly reduced.

[0066] Reference Figure 4 , is a schematic diagram of a variable gap capacitive sensor. On the left side of the figure is a set of flat plate capacitors. The gap adjustment component (active sensing component 1) located between the two plates is made of metal or has a metal surface material. Its length (proportion) in a set of plates can be adjusted. The plate area S and spacing D, the thickness of the gap adjustment component (Dd x1 -d x2) is fixed, let S 10 、C 10 They correspond to the plate area and capacitance of the gapless adjustment component, S 1x 、C 1x They correspond to the plate area and capacitance of the gap adjustment component, S=S 10 +S 1x According to the principle of capacitor series connection, we can get where d1 = d x1 +d x2 , Total plate capacitance C1 = C 10 +C 1x .right Figure 3 A similar conclusion is drawn from the analysis of another set of plates in the 20 +S 2x , C2=C 20 +C 2x For the convenience of analysis and calculation, it is assumed that the two sets of plates have the same size, and the side dimensions of their shared gap adjustment component (movable sensing component 1) are the same as the plates. When the movable sensing component 1 moves between the two sets of plates, it always has: S 10 +S 20 =S, S 1x +S 2x =S. By measuring C1 and C2 respectively, and calculating: Where s, D and d1 are constants, because S 10 There is a unique single-valued functional relationship between the size of and the specific position of the movable sensing component 1 between the two sets of electrode plates, so the horizontal displacement value of the measured part relative to the line connecting the two end points can be obtained.

[0067] Finally, it should be pointed out that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways without departing from the scope of the present invention.

Claims

1. A capacitive tensioning wire instrument, characterized in that: It comprises a movable sensing component (1) arranged on a reference line body, a first flat plate capacitor (2) and a second flat plate capacitor (3); A detection space is provided in each of the first flat-plate capacitor (2) and the second flat-plate capacitor (3), and the movable sensing component (1) is provided in the detection space; When the movable sensing component (1) is located in the detection space and is displaced, the capacitances of the first flat plate capacitor (2) and the second flat plate capacitor (3) change.

2. The capacitive wire tensioner according to claim 1, characterized in that: The movable sensing component (1) is provided with a hanging connection piece (11), and the movable sensing component (1) is connected to the reference line body via the hanging connection piece (11).

3. The capacitive wire tensioner according to claim 2, characterized in that: The hanging connection member (11) is made of non-metallic material.

4. The capacitive wire tensioner according to any one of claims 1 to 3, characterized in that: The movable sensing component (1) is made of metal.

5. The capacitive wire tensioner according to claim 4, characterized in that: The first flat plate capacitor (2) comprises a first plate (21) and a second plate (22), and the gap between the first plate (21) and the second plate (22) is a detection space; The second flat plate capacitor (3) comprises a third plate (31) and a fourth plate (32), and the gap between the third plate (31) and the fourth plate (32) is a detection space.

6. The capacitive wire tensioner according to claim 5, characterized in that: The movable sensing component (1) is a rectangular parallelepiped.

7. The capacitive wire tensioner according to claim 6, characterized in that: The surface of the movable sensing component (1) is parallel to the surfaces of the first electrode plate (21), the second electrode plate (22), the third electrode plate (31), and the fourth electrode plate (32).

8. The capacitive wire tensioner according to claim 7, characterized in that: The thickness of the movable sensing component (1) is smaller than the width of the detection space.

9. A displacement monitoring method, characterized in that: include, Build the reference line body; Set the measured part on the reference line; A movable sensing component (1) is provided on the measured part and is perpendicular to the reference line body; Two sets of flat plate capacitors are arranged outside the movable sensing component (1); When the measured part is displaced horizontally in a direction perpendicular to the reference line, the length of the movable sensing component (1) in one group of flat capacitors will decrease, and the length in the other group of flat capacitors will increase.

10. The displacement monitoring method according to claim 9, characterized in that: When the measured part undergoes horizontal displacement in a direction perpendicular to the reference line, the capacitances of the two sets of plate capacitors are calculated, and the horizontal displacement of the measured part is calculated based on the difference in the capacitance between the two sets of plate capacitors.

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